You might notice some engineers walking around the convention center with backpacks. Well, they’re not your standard backpacks. They’re actually housing gear for collecting data on the performance of wireless networks. 

Global Wireless Solutions (GWS) says it performed a baseline test on Monday to monitor the performance of the four major national carriers. Inside the convention center, testing showed that two tiers emerged on the voice networks, with AT&T and Verizon Wireless edging out Sprint and T?Mobile USA, according to GWS President and CEO Paul Carter. 

In terms of data, download throughput tests showed that T?Mobile’s HSPA+ network had no trouble keeping pace with Verizon’s LTE network, he reports. However, Verizon’s network exhibited variability in throughput and also had the most failed tasks of any carrier. AT&T’s network throughput came in right behind these two carriers, while Sprint’s EV-DO results rounded out the lower tier.

GWS also had a van perform testing along the roadways and parking lots surrounding the convention center. Outside, the voice performance on each of the four major wireless carrier networks averaged one failed call, while MetroPCS got hit with two failed calls.  

The Verizon LTE network was more stable and consistent than inside the convention center, according to GWS. Verizon and T-Mobile were again in the top tier on download throughput, but this time, T?Mobile struggled more with failed tasks. AT&T again was just behind each of these carriers on download throughput but was the only carrier of the top three to consistently deliver successful tasks both inside and outside. Clearwire came in quite a bit slower, with a significant amount of task failures, the testers say. Not surprisingly, Sprint’s and Verizon’s EV-DO (which would represent the Verizon iPhone user experience) networks rounded out the lower tier.

GWS engineers plan to continue their tests throughout the week.